Air curtain using ionized air



AIR CURTAIN USING IONIZED AIR Filed Aug. 1, 1966 2 Sheets-Sheet 1 FIG..]. FIG. 3

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A INVENTOR- BY EDWARD W. SIMONS $7M, M

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ATTORNEYS 20, 1968 E; w. SIMONS 3,397,631

AIR CURTAIN USI NG IONIZED AIR Filed Aug. 1, 1966 2 Sheets-Sheet 2 F|G 4 K EDWARD W. SIMONS Wr W Jemm ATTORNEYS United States Patent 3,397,631 7 7 AIR CURTAIN USING IONIZED AIR Edward W. Simons, Mill Valley, Califl, assignor to Dualjet Corporation, Mill Valley, Calif., a corporation of California Filed Augrl, 1966, Ser. No. 574,885 11 Claims. (Cl. 98-36) ABSTRACT OF THE DISCLOSURE A body of gas, like a curtain, is moved across and adjacent to at least one side of a body of gas in a predetermined area, at least one boundary of which is the gas of said curtain. Atmospheric air is at the opposite side of said curtain from the gas in said area. The gas of one of said bodies is ionized to provide a surplus of ions of one sign therein relative to the ions in said atmosphere to reduce friction between said bodies. Apparatus is provided to form said curtain, move it and ionize one of said bodies.

This invention relates to an improved method, and apparatus for maintaining a body of air in an artificially conditioned state, within a space that is open to the atmosice Another object of the invention is the provision of a method and apparatus for maintaining a predetermined body of air within a space that is laterally bounded by a curtain of moving air against substantial mixing of the air of said curtain with the air of said body and with ambient air around said body and curtain.

The word air wherever used may be considered the equivalent of the word gas wherever the same principle may be suitable for accomplishing similar results.

FIG. 1 is a diagrammatic view of a refrigeration system that incorporates different arrangements that may be aelectively employed or employed in different combinalOIlS.

FIG. 2 is a diagrammatic view of a system similar to that of FIG. 1 but providing several other arrangements that may also be selectively employed or employed in different combinations.

FIG. 3 is a diagrammatic view of a system similar to that of FIGS. 1, 2 but showing an added arrangement that may be used selectively or in different combinations.

, FIG. 4 is a semi-diagrammatic, vertical sectional view showing the invention applied to conditioning of air within phere along at least one side thereof, several examples of a which are shown in my US. Patents 2,862,369 and 3,143,952, of Dec. 2, 1958 and Aug. 11, 1964.

In the aforesaid Patent 2,862,369, a showcase is shown having a compartment in which a pair of adjoining air curtains are moved across one open side of the compartment. The inner curtain that adjoins the refrigerated air within the case is refrigerated and the outside curtain is substantially the temperature of the room air outside the case, except for such cooling thereof as may occur due to its contact with the inner curtain. The inner refrigerated air curtain is recirculated and is maintained at the desired low temperature and the outer one may be discharged into the atmosphere, or may be recirculated, as desired. In some instances, a plurality of adjoining pairs of air curtains are used with the air of the inner curtain and the one adjoining it being cooled and recirculated through conduits extending around the compartment, as shown in US. Patent No. 3,147,602, issued Sept. 8, 1964, to Sterling Beckwith, and at times a single jet of refrigerated air provides the curtain across the open side of the compartment.

In other systems, such as in US. Patent 3,063,254 of Nov. 13, 1962, to E. V. Dickson et al., and in US. Patent 3,063,256 of Nov. l3, 1962, toF. G. Lamb a jet of refrigerated air is moved across an open side of a com partment. In the latter instance the jet is divided to provide a plurality of adjoining curtains of air.

One of the problems encountered in such systems is the mixing of the air of the adjoining curtains with each other and with the air within the compartment, and the mixing of the air within the compartment with the air curtainadjoining it; resulting in entrainment and'a loss in efficiency.

The main-object of this invention is the provision of a method and means for materially increasing the efficiency of systems of the types hereinabove mentioned.

Another object of the inventionis the provision of a method, and apparatus, for substantially reducing the mixing of the air of a curtain extending across at least one open side of a compartment with the air at opposite sides of the curtain to thereby reduce entrainment of the air.at said opposite sides with the air. of the curtain.

.A further object of the invention is the provision of a method and apparatus for substantially reducing the mixing of the air of a single curtain with the air of an adjoining curtain moving in thesame direction.

'an open space. The view is taken along line 44 of FIG. 5.

FIG. 5 is, a cross sectional view of the arrangement illustrated in FIG; 4 as seen from line 5-5 of FIG. 4.

In each of the different arrangements shown in the drawings, a compartment for display or storage of food or other articles is provided, which compartment may be provided with shelves, if desired, and at least one side of the compartment is open, and a jet or curtain of moving air extends across the open side. The patents hereinbefore noted show several examples, and US. patents to E. V. Dickson et al., 3,063,253 of Nov. 13, 1962, and to F. G. Lamb, 3,063,256 of Nov. 13, 1962 show other examples in which the air of the jet is refrigerated.

In FIG. 1, a compartment, generally designated 1, is for food or other objects, within which shelves may be provided, if desired, as indicated in said patents.

A conduit for air extends around said compartment, which air is refrigerated to the desired degree by any conventional and suitable refrigerating means 3, one such being coils through which refrigerant is circulated, and across which the air is moved. The passageway 2 and other features mentioned, including those hereinafter described, may be incorporated in a cabinet generally designated 4, at least one side of which is provided with an access opening 5, for inserting and removing food or other articles from within the compartment 1.

The conduit or passageway 2 (FIG. 1) terminates at one end along the lower edge of the open side 5 of the compartment in an upwardly directed horizontally elongated discharge opening or nozzle 7 and the opposite end of the passageway terminates in a downwardly directed horizontally elongated inlet 8 that is along the upper edge of theope'n Side S, and which opening 8 is in opposed relation to nozzle 7.

' The means for circulating the air through the passageway'2 to discharge nozzle 7 aud across the open side 5 of the compartment to the inlet 8 may be any power driven airrn'over, or blower 9.

. By this structure, a single refrigerated jet or curtain 10 "is established across the open side 5 of the compartment 1 ambient air, since the principle of the present invention is not dependent upon the air being refrigerated, although the benefits in the field of cooling the air on showcase compartments and in other areas is apparent.

If this single jet 10 only is used, a mixing of the refrigerated jet with the air within the compartment and entrainment of the latter air with he jet 10 would occur, resulting in a substantial reduction in the velocity of the jet across space 5 together with a substantial increase in the heat load. Also entrainment and mixing of ambient air with jet would occur.

In FIG. 1, the air within the compartment may be ion ized by any suitable ionizing means 13, several types of which are shown and described in US. Letters Patents 2,589,613 of Mar. 18, 1952, issued to W. W. Hicks, and No. 2,928,942 of Mar. 15, 1960, issued to W. W. Hicks et al.

A surplus of ions of either sign can be provided in various ways and may be used but the employment of negative ions is preferable for various reasons.

Where only the air within compartment 1 is ionized and only a single jet 10 extends across the open side 5 of the compartment, it will be seen that the ionized air within the compartment, and ambient air outside the compartment will adjoin opposite surfaces or sides of the jet 10*.

Upon establishing the moving curtain 10 across one side of the air within compartment 1, and actuating the ionizer '13, the air within said compartment will circulate within the latter due to the drag efiect from its engagement with the jet 10, and the air within the compartment will be ionized. Ions within the compartment 11 will leak into the jet 10 until a balance of ions is achieved, and since the ions in both are of the same sign, there will be a repellent effect between the jet and the body of air within compartment 1. This repellent effect is evidenced by an increase in the velocity of the jet-air and in a reduction in the circulatory movement of the air within the compartment, since there is a reduction in the resistance to movement of the air jet relativeto the body of air within the compartment. Such increased velocity in the jet-air effects a corresponding reduction in the heat load of the jet and a more economical cooling of the air within the compartment.

The ionized air within the compartment provides a storage source of ions when said air and the jet 10 are saturated with said ions, and the leakage of ions from the jet curtain into the ambient air outside the compartment is relatively slow, hence in most instances, provision is made for automatic intermittent operation of the ionizer or ion generator 13, either at predetermined time intervals, or any other suitable means for maintaining the ion content of the air at a level that will result in substantially optimum efiiciency. Such control means may be in a control box 14 that includes a conventional rheostat for controlling the rate of generation of negative ions. Obviously continuous ionization may be employed if desired, with the generator adjusted to substantially maintain a balance of ions in the jet 10 and within the compartment air with a minimum of loss to the outside air.

At a certain point in the ionization of the air within the compartment-1, the velocity of the air of jet 10 will become constant at its higher rate, and in the foregoing example, this rate was substantially greater than the velocity of the same jet where there was no ionization of any of the air.

FIG. 1 also shows provision for ionizing the air jet 10 by positioning an ion generator "15 within passageway 2, and which generator may be electrically connected with control box 14 for actuation of the generator independently of generator 13 where the latter is inoperative, or for actuation simultaneously with the generator 13.

When generator 15 is actuated alone, and generator 13 is inoperative, the resultant increase in efiicicncy substantially corresponded to the increase in efficiency when only the air in compartment 1 was ionized. The velocity of the jet air increased and that of the compartment air decreased. The negative ions in the jet air would leak to the compartment air until both the compartment air and the air of the jet were similarly ionized and the repellent effect between the moving curtain and the compartment air resulted in the velocity changes of the same character as described where only-the compartment air was ionized by the generator 13.

From the foregoing, it is seen that the two limits to the required number of ions to be produced to maintain constant the increased level of efliciency are:

(a) a minimum to reach the balance level within a reasonable time, and

(b) a maximum beyond which the losses ofiset any additional gain in efliciency.

Where both of the ion generators 13, 15 are used, the build-up to the aforesaid balance level is faster than where only one or the other of the generators is employed, but the end result is similar.

In FIG. 1, provision is also made for providing a system that is generally the same as that shown in my aforementioned Patent 2,862,369. This is effected by providing a passageway 16 within the cabinet 4 one end of which terminates in a discharge opening or nozzle 17 alongside the nozzle or opening 7 and parallel therewith, while the other end is open to the ambient air outside the cabinet.

This nozzle or opening 17 is outermost relative to the compartment 1 and adjacent to the inlet 8 for the refrigerated air of jet 10- an airfoil 18 may be provided. Within said passageway 16 a blower 19 is positioned to draw the ambient air into and to move it through passageway 16 to the nozzle 17 for ejection generally parallel with jet curtain 10 to the airfoil 18 to provide a guard jet 20 between jet 10 and the ambient air. At airfoil 18 the jet 20 is discharged into the ambient air.

To distinguish between jets 10, 20, the former is designated the primary jet as has already been noted, and the latter the guard jet, and the nozzles themselves may be divided into parallel passageways to promote laminar flow of the jets substantially as shown in my aforesaid Patent 3,143,952. The velocity of the jets 10, 20 may be approximately the same, however the present invention is not intended to be restricted to laminar flow or to any particular velocity or differences in velocities.

An ionizer 23 may be positioned within passageway 16 to ionize the guard jet with negative ions, or ions of the same sign as produced by generators 13-, 15. Inasmuch as the air of the guard jet in this instance is not recirculated, it nevertheless cooperates with the primary jet to ionize the air of the guard jet for reducing the mixing of the air of primary and guard jet by the repellent action of the surplus of negative ions in each jet.

In FIG. 2, a cabinet generally designated 24, is shown having an interior compartment 25 in which shelves may be positioned or not, as desired.

In the arrangement shown in FIG. 2 an outer passageway 26 and an inner passageway 27 are provided, the former terminating at one end in a generally downwardly directed discharge nozzle 28 for directing a jet curtain 29 downwardly across an open side 30 of the compartment 25 and to lower horizontally elongated opening 33 extending along the lower edge of the opening 36.

Within passageway 26 is any suitable refrigerating means 34 for refrigerating the air in passageway 26 and a blower 35 for circulating the refrigerated air of the jet through the passageway and across the open side of the compartment.

The inner passageway 27 opens at one end in a discharge opening 38 adjacent to and parallel with nozzle 28 for discharging air across the open side of the compartment and to an intake opening 39 alongside and parallel with the intake opening 33, The nozzles 38, 39 are arranged to provide for how of air across the open side of the compartment, with jet 40 being the inner jet in adjoining relation to jet 29.

Refrigerating means 43 is within passageway 27 for cooling the air passing therethrough to the desired degree, and-a power driven blower '44 is provided for moving the air to provide jet 40;

The arrangement in FIG. 2 differs-from that of FIG. 1 in that the air of one or both jets may be refrigerated, and the jets move downwardly instead of upwardly. Insofar as this invention is concerned, the direction of movement of'thejetsis immaterial. It is to be understood that the air conditioning or refrigerating means 34 may or may not be used, and if not used, the result will be similar to the result of the system of FIG. 1 except that the outer jet 29 will become a refrigerated guard jet.

"Ion generator 45 is provided for generating negative ions within the compartment 25, while similar generators 46, 47 are respectively positioned in passageways 26, 27 for ionizing the air of jets 29, 40 with negative ions. Each of the generators may be actuated simultaneously or in any desired intermittent sequence with the others, or alone.

Upon ionizing the air in compartment 25 the ions will leak into and saturate or substantially saturate both jets with negative ions to effect repulsion of the jets relative to each other and to the air in the compartment. The ionization. may be accelerated by actuating the generators 46, 47- at the same time, or as has been explained where dual jets are used in the example shown in FIG. 1 either of thejets may be ionized alone and the ultimate result will be a leakage of or migration of the negative ions into the other jet and into the air of the compartment.

'- -Where dual'or multiple jets are used, and the air in the compartment becomes saturated, as well as that of the jetsythe increase in velocity of the jets will increase from about 8 percent to about percent over the velocity where there is no ionization.

Insofar as the refrigeration of the air of jets 29, 40 are-concerned, they may be refrigerated to generally the same or to different degrees. In some instances air may be diverted from the inner passageway 27 into the compartment through one or more openings 48 for cooling produce that may be in compartment 25 or on shelves within the latter.

The same control system for continuous, intermittent and selective operation of the ion generators may be used as described for the system in FIG. 1.

-In FIG. 3, the cabinet 49 has compartment 50 therein and an open side 53. An outer passageway or conduit 51 extends around the compartment within the cabinet, one end terminating in a horizontally elongated upwardly opening intake 54 along the lower edge of the opening and the opposite end terminates in a downwardly directed horizontally elongated discharge nozzle 55 that is opposed to the inlet 54.

Within conduit 51 air therein is circulated by a blower 56 from the inlet 54 to outlet 55 and in the form of an outer or guard jet curtain 57 across the open side 53 back to inlet 54. Any suitable conventional refrigeration means 58 within passageway 51 may be used to refrigerate the air to cool the air of jet 57.

Inwardly of passageway 51 is a similar passageway 59 that extends around the three sides of the compartment 50 and'that terminates at one end in an inlet opening 60 that is parallel with and alongsideinle-t 54. The opposite end of'passageway 59 terminates in a discharge nozzle 63 that is alongside and parallel with nozzle 55, and air discharged therefrom is directed across the open side 53 in a jet64 parallel with and adjoining jet 57.

The air in passageway 59 is circulated in the same manner as the air in outer passageway 51 by a blower 65 and may be moved over refrigerating means 66 that is similar to'the refrigerating means 58. Blower 65 and the refrigeration means 66 are within passageway 59.

An innermost passageway 67 also extends around the compartment 50, adjacent to passageway 59, and one end thereof terminates in an inlet 68 while the other end terminates in a discharge nozzle 69. Inlet 68 is alongside inlet 60 while the discharge nozzle 69 is alongside nozzle 63, and they are positioned similar to the inlet 60 and discharge nozzle 63 to provide an inner jet 70 parallel with and adjoining the jet 64.

A blower 73 in passageway 67 circulates-the air therein and across the open side 53 of the compartment 59, and refrigerating means 74 in passageway 67 cools the air of jet 70.

By the foregoing arrangement the several refrigeration means 58, 66 and 74 may be selectively operated and also controlled in the conventional manner to cool the air of jets 57, 64, 70 to different degrees. If desired, the refrigeration means 58 in the outer passageway 51 may be inoperative and a door 75 at the lower front side of the cabinet opened so ambient air may be drawn into passageway 51 for circulation, and to form jet 57 instead of refrigerating the outer curtain.

Within the compartment 50 an ion generator 76 may be positioned, and similar genera-tors 77, 78, 79 may be respectively positioned within passageways 51, 59 and 67, each adapted to generate ions of the desired sign, and said generators may be electrically connected with a control box for actuating the generators selectively, simultaneously, or in any desired combination.

Referring to FIGS. 4, 5 the principle described hereinbefore may be applied to an isolated portion of an open area, generally designated 90, which area is within the confines of the upwardly projected outline of a pair of upwardly directed, concentric, annular adjacent air inlets 91, 92.

Spaced above and coaxial with inlets 91, 92 is a pair of downwardly opening, adjacent, annular discharge nozzles 92, 93 respectively directed toward inlets 92, 93.

A circular horizontally disposed circular bottom wall 95 extends across the space enclosed by the inner inlet 91, which is the innermost inlet of the pair thereof, and a similar circular, horizontally disposed, circular top wall 96 is enclosed within the inner nozzle 93. Walls 95, 96, respectively extend to the inner inlet and to the inner nozzle.

Spaced below bottom wall 95 is a circular, horizontal, lower partition wall 97, and spaced below partition wall 97 is a lower horizontal, circular wall 98. These walls 97, 98 are coaxial with bottom wall 95, and partition wall 97 is of greater diameter than the diameter of the wall 95, while lower wall 98 is of larger diameter than the diameter of the partition wall.

Walls 95, 97, 98, respectively, may have cylindrical walls 99, 100, 101 extending upwardly from their outer circular edges with their upper edges defining the sides of inlets 91, 92 (FIG. 4).

Circular horizontally disposed walls 104, 105 are successively space above upper wall 96 in coaxial relation to the latter, with walls 104, 105 of successively greater diameter than wall 96, and cylindrical walls 106, 107, 108, respectively extend downwardly from the outer edges of walls 96, 104, 105 to define the annular nozzles 93, 94. The latter may include parallel separate, downwardly directed parallel passageways to direct the air ejected from the nozzles toward the inlets 91, 92.

Any suitable means such as vertical spaces 109 may be disposed between the walls 95, 97, 98 and between walls 96, 104 and 105 to space them apart the desired distance and the distances the walls 104, 105 and walls 97, 98 successively extend beyond the wall 96 and wall 95 is substantially the same, as the spacing between adjacent pairs of the walls respectively at the top and bottom of the apparatus.

A central outlet pipe 110 extends downwardly from a central opening in the lower partition wall 97 for downward passage of air from space 112 between the bottom wall 95 and the lower partition wall 97 therebelow, while an outer cylindrical wall 113 concentric with and spaced around pipe 110 extends downwardly from a central opening in wall 98 to provide an annular passage for the air in space 114 between the lower partition wall 97 and the wall 98 therebelow.

A similar structure is at the'upper portion of the apparatus, in which an upwardly extending central pipe 115 extends upwardly from'a central opening in upper partition wall 104 for passage of air into the space 116 between walls 96, 104. An outer cylindrical wall117 co ncentric with and spaced around'pipe 115'extends up wardly from a central opening in wall 105m passage of air into space 118.

An outer passageway 119 extends outside of space 90 from the lower end of pipe 110 to the upper end of pipe 115, and an inner passageway 120 extends from the lower end of lower cylinder 113 to the upper end of the cylinder 117. These passageways extend radially outwardly from the ends of pipes 110 and 115 to one side of space 99, and then vertically, and they are preferably parallel and in side-by-side relation with intermediate wall common to both passageways.

Where the apparatus is indoors, a concrete or any other suitable floor or base 123 may support the wall 98 with the passageways 119, .120 below said floor, or the structure may be supported on a platform above the floor.

A suitable blower 124 and a refrigeration means 125 may be positioned within passageway 119 for moving the air therethrough from inlet 91 to nozzle 93 for producing an inner primary jet curtain 126 fully enclosing the area 90. A blower 127 in passageway 120 will move the air therein from inlet 92 to the discharge nozzle 94 for providing an outer guard curtain 128 adjoining and outside of the primary jet curtain 126. The air in the outer curtain may be refrigerated, or otherwise treated, if desired, and ionizers 129, .130, 131 may be respectively positioned within space or area 90, and in passageways 119, 120 to provide surplus ions of the desired sign for repulsion of the jets and air of space 90 for accomplishing the results described. Any desired combinations of ionizers may be used, although the air in area 90 will be isolated by the jets alone, irrespective of ionization. It is also obvious that a plurality of pairs of adjacent jets may be used, as in FIG. 3 but in any event a primary and a guard jet are preferably used.

In the present invention the units or means indicated for refrigerating the air may be designated air conditioning units or means, whether for temperature conditioning or otherwise. The ionizing of air of the jet curtains or the area that is isolated in any of the disclosures is conditioning such air.

In the example shown and described in FIGS. 4, the space 90 may be of any outline, such as polysided or elliptical etc., according to the shape of the inlets and discharge nozzles associated therewith. The area or space 90 may be wholly open at all sides, except for the jet curtains, or it may be closed on one or two sides. For example, in an operating room in a hospital the air within an area wholly open on several or all sides may not only be maintained sterile at a certain desired temperature. Two adjoining sides of a room in a corner of the latter may be conditioned by providing one or more pairs of jet curtains closing off the corner; whereby the air within said corner may be kept sterile and at the desired temperature.

In each of the disclosures hereinbefore made, generically speaking, there is a body of gas within an area of predetermined boundaries, one'or more of which boundaries comprises a pair of bodies in the form of an adjoining pair of gaseous curtains having different characteristics extending across one side of said body of gas with one curtain of said pair adjoining said body of gas and with the other curtain outward of said onecurtain relative to said body, and the present method as applied to the foregoing comprises the steps of moving the gas of said curtains in one direction across said one side of said body of gas, and at the same time ionizing the gas of at least one of said bodies to provide a surplus of ions therein of one sign to thereby reduce the frictional resistance between the body so ionized and the body adjoining it.

While air is the gas described in connection with the illustrations, the principle of ionizing one or more of the bodies thereof to reduce mixing of the gas of the different bodies thereof with each "other, by resultant repulsion of the gas of the adjoining bodies, would be of utility whether the distinguishing "differences between the gas in the area being conditioned, and atmospheric air, were temperatures, moisture content, or chemical content.

With the relative widespread adoption'of air refrigeration systems to showcases of the type disclosed in the patents mentioned herein, the application of the present principle to such systems is relatively simple and practical. However, the beneficial results from use of the principle where the air within a predetermined area is to be conditioned or maintained in'a condition different from that of atmospheric air, are realized where the desired condition of the gas that is in said area may be one of sterility, humidity, or such gas may be medicated, etc. Normally such gas is air, but in relatively small areas where operations may be performed by an operator outside the area, or Where a process may involve subjecting an object to a particular gas with instant access thereto from the outside, other gases than air may be used.

It is to be understood that changes and modifications may be made in the invention as hereinabove specifically described and shown, and that come within the scope of the following claims, without departing from the spirit of the invention.

I claim:

1. In the method of isolating a body of gas within an area having predetermined boundaries, from atmospheric air, at least one of which boundaries includes a body of gas in the form of a curtain extending across one side of said body of gas within said area, the steps comprismg:

(a) moving the gas of the body providing said curtain in one direction across one side of the body of gas within said area in opposed, adjacent relation to said last mentioned side;

(b) ionizing the gas of one of said bodies to provide a surplus of ions of one sign therein relative to the ions in the atmospheric air outside said area.

2. In the method of isolating a body of gas within an area having predetermined boundaries, from atmospheric air, at least one of which boundaries includes a body of gas in the form of a curtain extending across one side of said body, the steps comprising:

(a) moving the gas of the body providing said curtain in one direction across one side of the body of gas within said area;

(b) ionizing the gas of one of said bodies to provide a surplus of ions of one sign therein relative to the ions in the atmospheric air outside 'said area; i

(c) maintaining the gas of said bodies in substantially adjoining relation during said movement of the body providing said curtain, whereby leakage of ions from one body to the other will occur to effect a balance between the ions therein "in excess of the ions in said atmospheric air. 1' V 4 3. In the method as defined in claim 2,

(d) said ionization of thegas of one of said bodies being substantially icontinuous until said balance is efliected, and thereafter I (e) intermittently ionizing the gas in said one of said bodies' to substantially maintain only approximately said balance of ions in"saidjbodies.

4. In the method for conditioning a body (if gas within an area having predetermined boundaries, one or more of which boundaries comprises a pair of bodies in the form of apair of opposed adjoining gaseous curtains having different characteristics extending across one side of said body of gas with one curtain of said pair adjoining said body of gas and with the other curtain outward of said one curtain relative to said body, the steps comprising:

(a) moving the gas of said curtains in one direction across and in engagement with said one side of said body of gas;

(b) ionizing the gas of at least one of said bodies to provide a surplus of ions of one sign therein relative to the gas of an adjoining body, whereby the gas of said one of said bodies will be repellant to the gas of the adjoining body thereof.

5. In the method as defined in claim 4,

(c) the body of gas so ionized including the said body of gas within said area.

6. In the method as defined in claim 4,

(c) the body of gas so ionized including the body forming the gaseous curtain adjoining the body of gas within said area.

7. In the method as defined in claim 4,

(c) the body of gas so ionized including the body forming the gaseous curtain outward of said one curtain.

8. In the method as defined in claim 4,

(c) maintaining said bodies of gas in adjoining relation during ionization of said one of said bodies and continuing the ionization of the gas in said one of said bodies until the ions in said sign in said walls are approximately in balance, due to leakage of ions between said bodies, and thereafter,

(d) intermittently ionizing the gas of said one of said walls to substantially maintain said balance.

9. The method of isolating the interior of a compartment having an open side from the influence of ambient atmosphere and maintaining a predetermined air condition within said compartment other than atmospheric that comprises the steps of:

(a) conditioning the interior of said compartment to said predetermined air condition;

(b) simultaneously moving a pair of substantially parallel and substantially contacting layers of air across the open side of said compartment in the same direction;

(c) one layer of said pair being approximately at said predetermined condition and defining a substantially continuous air curtain at said open side next to the air within said compartment;

(d) the other layer of said pair being at the side of said one layer outwardly o fsaid compartment;

(e) ionizing the air of said compartment and said one layer with a surplus of ions of one sign relative to the ions of atmospheric air to thereby reduce the friction between the air of said one layer and the air within said comparement at their adjoining faces.

10. In the method as defined in claim 9,

(f) the said ionization of the air within said compartment and said one curtain being effected by direct ionization of the air within either said compartment or said one curtain and thereafter leakage of ions from the air being directly ionized, to the air of the other.

11. Apparatus for conditioning a body of gas within a predetermined area, at least one side of which area is open for substantially free movement of objects from ambient atmospheric air outside said area into and out of the latter, and which apparatus includes a conduit for gas outside said area terminating at one of its ends in a horizontally elongated discharge nozzle, and in a horizontally elongated inlet respectively defining two opposite boundaries of said open side with nozzle and said inlet directed toward each other for ejection of gas from said nozzle toward said inlet to provide a gaseous curtain movable from said nozzle to said inlet in engagement with the gas in said area:

(a) means for ionizing the gas in said area or in said conduit to provide a surplus of ions of the same sign in the gas or said area or the gas in said curtain relative to the ions in the ambient air outside said area whereby the gas in said area and in said curtain will repel each other along their adjacent faces for reducing the frictional resistance between them.

References Cited UNITED STATES PATENTS 3,130,559 4/1964 Beckwith 6289 X 3,163,024 12/1964 Beckwith et al. 62-89 X ROBERT A. OLEARY, Primary Examiner.

W. E. WAYNER, Assistant Examiner. 

